1. Field of the Invention
This invention relates to interfaces and, in particular, to a manual interface that combines continuous and discrete control and display capabilities. Most particularly, the invention relates to a manual interface that combines the continuous control and display capability of a haptic interface with the discrete control capability of a discrete selector (such as a tagged object).
2. Related Art
There are a variety of situations in which a person interacts with an environment via an interface. (What can constitute an “environment” and the types of interaction that a person can have with an environment—which typically will depend upon the nature of the environment—are discussed further below.) Herein, each point of interaction between a person and an environment is referred to as an “interface.” An interface can be used for input to, and/or output from, the environment. Interface devices can take a variety of forms, such as, for example, visual interface devices (e.g., computer display monitors, televisions, video cameras, LED displays, signal lights), auditory interface devices (e.g., speakers, microphones), haptic interface devices (e.g., joysticks, keyboards, mice) and tagged objects (explained further below).
A haptic interface device can, as well, take a variety of forms, and can be used as an input device and/or an output device. Haptic interface devices can include force feedback interface devices (i.e., devices which display to the kinesthetic sense) and tactile interface devices (i.e., devices which display to the tactile sense). A force feedback interface device enables variation in a force transmitted to the person using the interface device in response to use of the interface device. A tactile interface device displays to other aspects of the sense of touch, such as, for example, texture or temperature. A haptic interface device can also display to both the kinesthetic and tactile senses, i.e., combine the capabilities of a force feedback interface device and a tactile interface device. For example, a force feedback interface device can, with appropriate application of force, also simulate textures (e.g., bumpiness in a surface that is felt through a probe).
FIG. 1 is a block diagram illustrating the functional aspects of a conventional system including a conventional haptic interface device. A haptic interface device 101 communicates with a haptic controller 102 which, in turn, communicates with an environment 103. The haptic interface device 101 can be used to enable a user 104 to effect, via the haptic controller 102, a particular interaction with the environment 103 and/or can provide a haptic sensation to the user 104 in accordance with the interaction with the environment 103. Often, the environment 103 is also displayed to the user 104 via another device (e.g., one or more devices that produce a visual and/or auditory display), though this is not necessary (as indicated by the dashed line in FIG. 1). (A device for providing haptic sensation to a user can also be constructed to provide other types of display to the user, such as a visual and/or auditory display.) The haptic interface device 101, haptic controller 102 and environment 103 can be embodied by any of a variety of appropriate physical devices which can be controlled in a variety of ways. For example, a brake or a computer-controlled motor can be used to selectively apply a force that impedes or augments motion of a knob or handle that a person uses to change the state of a visual display (e.g., move an icon on a display screen or traverse a visual recording).
A haptic interface device is useful in effecting continuous control and display of an environment. However, there can be significant disadvantages in using a haptic interface device for discrete control. For example, use of a haptic interface device to change between discontinuous states of an environment may be confusing in some situations without another display (e.g., a visual display or an audio display) to augment the haptic interface device. Moreover, addition of another display to minimize or eliminate such confusion may undesirably divert the attention of the person using the haptic interface device and, in any event, adds complexity and expense to the overall interface. Additionally, use of a haptic interface device to effect discrete control may be unwieldy in some situations (see, for example, the description with respect to FIG. 6 below), since a haptic interface device may necessitate traversal of a large number of states between a current state and a desired state. Further, a haptic interface device may be an unnecessarily complex and expensive device to effect discrete control. Finally, it may be desirable for a discrete control device to be relatively small and portable: a haptic interface device can be undesirably deficient in this regard.
Another class of interface device, sometimes referred to as a “tagged object” or “tangible user interface (TUI) device” (for simplicity, “tagged object” is used hereinafter to refer to such an interface device) is a physical object, which can be imbued with some degree of computational capability (e.g., a processing device, a memory device), that affects the interaction of a person with an environment in a particular discrete manner in accordance with an identity or a state of the tagged object. Often, the computational capability (if present) is relatively simple. Typically, a tagged object is a relatively small and inexpensive object, and can be portable.
FIG. 2 is a block diagram illustrating the functional aspects of a conventional system including a conventional tagged object. One of multiple tagged objects 201 is selected by a user 204. The tagged object 201 communicates with a set of filters 202 which, in turn, communicate with an environment 203. The selected tagged object 201 causes, via selection of one or more of the filters 203 corresponding to the tagged object 201, the interaction by the user 204 with the environment 203 to be affected in a particular manner. The tagged object 201, filters 202 and environment 203 can be represented by any of a variety of appropriate physical devices which can be controlled in a variety of ways. For example, a block including an electronic identification device can be placed in a corresponding holder that senses the identity of the block and marks a part or parts of a visual recording with the block's identity or locates a part or parts of a visual recording in accordance with the block's identity. Tagged objects and their uses are described in more detail in, for example, “Bricks: Laying the Foundations for Graspable User Interfaces,” by G. Fitzmaurice et al., Proceedings of the Conference on Human Factors in Computing Systems (CHI '95), ACM, Denver, May 1995, pp. 442-449; “Tangible Bits: Towards Seamless Interfaces between People, Bits and Atoms,” H. Ishii et al., Proceedings of the Conference on Human Factors in Computing Systems (CHI '97), ACM, Atlanta, Mar. 1997, pp. 234-341; “Logjam: a tangible multi-person interface for video logging,” J. Cohen et al., The Conference on Human Factors in Computing Systems (CHI '99), Pittsburgh, 1999; and “Bridging Physical and Virtual Worlds with Electronic Tags,” R. Want et al., The Conference on Human Factors in Computing Systems (CHI '99), Pittsburgh, 1999, the disclosures of which are incorporated by reference herein.
A tagged object is useful in effecting discrete control of an environment. However, there can be significant disadvantages in using a tagged object for continuous control. For example, a user must sequentially interact with multiple tagged objects to effect continuous control. It may be necessary to use a prohibitively large number of tagged objects to achieve continuous (or even nearly continuous) control. Further, it is typically desirable to effect continuous control by interacting with a single device, rather than with a series of devices. Additionally, it may be difficult or impossible in some situations to achieve an adequately fine degree of control using a tagged object.
Additionally, a tagged object typically only has input capabilities and does not provide feedback (display) regarding a person's interaction with an environment. (This is so because a tagged object is typically a relatively simple portable device, and the addition of display capabilities may introduce undesirable complexity or detrimentally impact the portability of the device.) Thus, a tagged object may not provide as rich an interaction as desired. (However, a tagged object can be augmented to include a device that provides display capability, usually a simple, low power consumption, discrete display device, such as an LED.)
As made clearer by the description below, it would be desirable for an interface to have both continuous and discrete control and display capabilities. In particular, it would be desirable for a manual interface to have both the continuous control and display capability of a haptic interface and the discrete control capability of a tagged object.